Fig. 4. Mannose protects against DSS-induced epithelial tight junction disruption through its effects on mitochondrial function.

a–c Normal colonic epithelial NCM460 cells were treated with 2.0% DSS in combination with or without mannose (25 mM) for 24 h. a MitoTracker was employed to mark mitochondria. Mitochondrial ROS and the mitochondrial membrane potential were measured by MitoSOX and JC-1 probes, respectively. Scale bar = 20 μm. b The cellular OCR was evaluated using a Seahorse Bioscience XF24 Extracellular Flux Analyzer. The quantification data of basal OCR, maximal OCR, and ATP production are presented. c The expression of OXPHOS proteins in the mitochondrial fractions was determined by western blot analysis. The levels of PDHK1 and PDH were examined by immunoblotting analysis. d NCM460 cells were pretreated with the mitochondrial electron transport chain complex I inhibitor rotenone (5 μM), followed by DSS and mannose treatment. The expression of ZO-1, occludin, and claudin-1, 2, and 4 in the cells was determined by western blot analysis. e NCM460 cells were cultured with DSS and mannose for 24 h in the presence or absence of mito-tempo (2 μM). The expression of ZO-1, occludin, and claudin-1, 2, and 4 in the cells was determined by western blot analysis. *P < 0.05, **P < 0.01, and ***P < 0.001. Data were analyzed by an unpaired Student’s t-test (a–e) and shown as means ± SD. Data from one representative experiment of three independent experiments are presented. Source data are provided as a Source Data file.